I would think that the answer is Los apodos en los países.
Explanation:
It cant be Las amigas de Eulalia because the text doesn't talk about her friends. It also wouldn't be Los trabajos de los tiod de EUlalia because again, the text does to say anything about her Uncles' jobs.
The main point can also not be Las fiestas en las families because the text only mentions a party for a single sentence.
The only answer choice left is Los apodos en los países.
